TSH is a pituitary hormone that stimulates the production of thyroid hormone by the thyroid gland. This production can be blocked by sodium perchlorate (SP), which inhibits the cellular import of iodine necessary for thyroid hormone synthesis. What would be the effect of TSH or SP exposure, respectively, on the timing of metamorphosis in frog larvae?
A) Premature metamorphosis; premature metamorphosis B) Premature metamorphosis; delayed metamorphosis C) Delayed metamorphosis; premature metamorphosis D) Delayed metamorphosis; delayed metamorphosis